@Gekko_s What do You mean by that? Is it possible, that other cars around the city have different plates? Well, You should already notice that? Do You mean, is it possible to use multiple license plates on a single car? Answer is no, unless You are going to add simple 3d-models of other plates to Your car and they will stay non-working.

@Gekko_s Hmm, I still think, that they all havent got the same. For example, coppers should have their own plate (SA EXEMPT?), but now I understand You. This problem and solution lies in "carvariations.meta". This file controls the license plate probabilities of all cars in-game. Find Your interested car entry and just change the lines.

@Gekko_s Game supports 6 types of license plates, which all exist in-game. If you want, You must replace them manually into Your beloved ones (EU-plates). Just remember, which plate are You replacing with what and after that, write proper probabilities.

You can have a situation in-game, that you met Your E63AMG with different plates around the city, if You configure them right.

EDIT: I forgot, some modders managed to get plates working as add-ons also, but it is definately harder for You right now.